The subject of the present invention is a power pick-up assembly for a railway vehicle, of the type comprising a pantograph and a pantograph support, the pantograph support comprising a stationary chassis for mounting on the roof of a railway vehicle, and a mobile chassis carrying the pantograph and connected to the stationary chassis to tilt laterally with respect thereto on each side of a position of rest.
The invention applies, in particular, to a tilting railway vehicle.
Such a railway vehicle is designed so that its body shall adopt a lateral inclination with respect to the axis of the axles of its bogies in the curved parts of railway lines.
If an assembly is mounted on top of the railway vehicle for picking up power from an overhead power line, it then becomes necessary for the pantograph to be inclined laterally with respect to the body in the opposite direction to the direction in which the body is inclined with respect to its axles, so as to limit the lateral movement of the collector bow of the pantograph with respect to the contact line of the overhead power lines.
This is because if there were no such inclination of the pantograph in the opposite direction, known as tilt compensation inclination, the relative movement of the collector bow with respect to the contact line could be great enough for the line to be in contact only with the insulated parts of the collector bow or even spaced laterally from it, and this could cause damage to the overhead line and to the pantograph, particularly as the body returns to its position of rest.
Document EP-A-785,100 describes a power pick-up assembly of the aforementioned type in which the mobile pantograph support chassis is connected by four link rods to the stationary chassis. At rest, that is to say when there is no tilt compensation, the points of articulation of the link rods transversely form a downwards-converging trapezium. The lateral movement of the mobile chassis causes the pantograph to be inclined laterally with respect to the body.
The lateral movement of the mobile chassis is brought about by means of one or more rams which thrust the mobile chassis laterally and which is or are arranged on one side or both sides of the pantograph support. A control system steers the ram(s) to move the mobile chassis and provide the pantograph with tilt compensation.
To ensure satisfactory movement of the mobile chassis while at the same time limiting the unwanted movements in translation and rotation, it is appropriate to provide guides against which the mobile chassis slides, and to fit a central lateral ram on each side of the mobile chassis.
Correct operation of the power pick-up assembly therefore entails a complex bulky structure which is subject to dissipation of mechanical energy by rubbing at the guides which thus constitute wearing parts.
The substantial bulk of a power pick-up assembly of this kind is a particular hindrance in complying with size requirements imposed on railway vehicles without limiting the headroom available for the passengers within the vehicle.
One object of the invention is to provide a power pick-up assembly of the aforementioned type which allows the mobile chassis to be guided satisfactorily and which has a relatively simple structure.
To this end, the subject of the invention is a power pick-up assembly of the aforementioned type, characterized in that the mobile chassis is connected to the stationary chassis by two tilting rigid lateral supports, each tilting support being articulated, on the one hand, to the stationary chassis at two longitudinally-spaced points and, on the other hand, to the mobile chassis at two longitudinally-spaced points.
According to particular embodiments, the power pick-up assembly may comprise one or more of the following characteristics, taken in isolation or in any technically feasible combination:
each tilting support comprises a yoke articulated by its branches to the stationary chassis, and two clevis mounts which extend the base of the yoke and which are articulated to the mobile chassis;
each tilting support has a transverse profile with its concave aspect facing towards the inside of the power pick-up assembly;
the clevis mounts of each tilting support are roughly orthogonal to the branches of the corresponding yoke;
the points by which the tilting supports are articulated to the mobile and stationary chassis form, transversely, a trapezium which converges downwards when the power pick-up assembly is mounted on the roof of a railway vehicle and when the mobile chassis is in the position of rest
A further subject of the invention is a railway vehicle comprising a power pick-up assembly mounted on the roof of the vehicle, characterized in that the power pick-up assembly is an assembly as defined hereinabove.